Spectators of various outdoor events, such as golf, baseball, soccer, fireworks displays and parades, for example, typically use lawn chairs for seating during the event. Seating is commonly placed on nearby grass areas that may or may not be flat. A broad range of portable, folding and compact outdoor chairs is available in today's market but their designs are optimized for level or horizontal surfaces. The chairs are not the problem. Rather it is the way the various portable chairs are used on sloping terrain.
Depending on the angle of the ground to horizontal, or slope, the seat of most chairs remains roughly parallel (actually around 6°) relative to the ground upon which it is situated, that is, assuming that the seated individual is facing downhill. As the slope of the ground increases, the angle of an individual's seated position relative to horizontal decreases. As the seating angle decreases and then becomes negative, the seated individual's constant attempt to brace himself to keep from sliding out of the chair or to keep the chair from toppling does not create a situation of relaxed comfort, an important goal of sitting in a chair in the first place. At some point of discomfort individuals, with nothing more than a fixed-leg lawn chair, may very well elect to sit on the ground or try to find flatter ground for their chairs rather than fight the slope. Unfortunately, flatter ground simply may not be available or may offer an inferior viewing perspective of the event being observed.
In order to compensate for various slopes, the legs of a chair should be easily and continuously adjustable to adapt to a wide degree of slopes in order to maintain a somewhat normal and comfortable seating angle. In addition, since a portable chair may be subject to rules and restrictions at certain spectator events, a chair's capacity to adapt to sloping terrain seating may be subject to certain physical limitations. For example, the rules covering portable seating at the Memorial Golf Tournament held at the Muirfield Village Golf Club in Dublin, Ohio prohibit, among other things, chairs with arms and chairs over a certain height. Finally, since seated attendees at an event may be already burdened with other carried items, a portable chair should be both lightweight and quickly adjustable.
Numerous attempts to solve this seating problem have resulted in patents being granted for various configurations of adjustable portable chairs. However, as will be evident from the discourse below, each of these attempts have shortcomings, which prevent them from fully achieving a practical solution to the slope problem which may stem from the difficulty in use or the cost to manufacture.
For example, U.S. Pat. No. 4,772,068, issued to Glecker et al., discloses a portable fishing chair intended for use on sloping terrain by fishermen and campers. Glecker et al.'s chair employs an adjustable extension that is limited to three fixed positions, which accommodates only three different degrees of slope. The chair is not easily adjustable from the multiple, fixed seating positions and appears relatively complicated. In addition, the chair has arms, which would prevent it from being used at certain events.
U.S. Pat. No. 5,494,333, issued to Wilson, discloses a chair, which provides either three or four individually adjustable legs such that the chair can be used on a variety of terrain. Like Glecker et al. the number of positions is fixed and thus cannot conform continuously to a wide degree of slopes. The legs do not appear to be easily adjustable by a user in a seated position. Like the Glecker chair, the Wilson chair has arms and thus would not conform to events where armed chairs are not permitted.
U.S. Pat. No. 5,522,642, issued to Herzog, discloses a folding stool, with individually adjustable legs, that is adaptable for use on various sloped terrains. However, like the other chairs in the cited art, the legs are not adjustable from a seated position and adjustment is limited to a fixed number of angles based upon predetermined, fixed hole spacings. While Herzog has no arms, its ability of increasing the height of the stool for better viewing over crowds would violate chair policies for events, which regulate the maximum allowable seat height for portable seating.
U.S. Pat. No. 6,036,148, issued to Shank, discloses a folding outdoor chair having four, independently adjustable legs. However, like the other chairs in the cited art, the legs do not appear to be easily adjustable from a seated position and would require multiple settings of the various legs.
U.S. Pat. No. 6,361,107, issued to the Applicant, John G. Alexander, discloses a folding stool and chair that is adjustable by a seated individual over a continuous range of slopes. While Alexander represents significant advancement over the art, it is somewhat heavy, expensive to fabricate and may require more than one hand to return the chair legs to their fully extended position.
What is needed is sturdy, lightweight, durable and portable lawn furniture that has a comfortable seat and that can be easily adjustable to varying terrain by the user from a seated position.